QUANTICO, VA (CBS) -- Three Marines are dead in an apparent murder suicide at the Marine Base Quantico about 40 miles south of Washington, DC. Investigators are trying to piece together a motive, to why a Marine would turn on his own.

For Alan Melton the owner of the Stars and Stripes Cafe near the Marine Base Quantico, hearing about the death of a Marine is never easy, but death of three Marines in an apparent murder suicide is tragic. He says, "It's hard to believe something so close to home could really happen, especially on a Marine Corp base, where you think it's nice and safe."

At around 10:30 Thursday day night, authorities responded to a 9-1-1 call and found one Marine, a male- dead from a gunshot wound in a barracks on the Marine Base at Quantico.

The base went on lockdown, and the apparent shooter, then went to another part of the barracks, where he apparently shot female Marine, before turning the gun on himself. Col. David Maxwell, Commander, Marine Corp Base Quantico says, "The shooter, an active duty Marine, was pronounced dead by a self-inflicted gunshot wound, by law enforcement at the scene."

It's been a rough few days for the Marines. This shooting marks the second tragedy to hit the Corp in less than a week. On Monday, seven Marines were killed in an explosion during a training exercise in Nevada.

At the Marine Corp League Bar, Bartender Melody Myers says this tight knit military town will be looking for answers. She says, "I think people are very concerned about it. There are three people, three Marines that are dead right now."

Marine officials are still searching for a motive, but did say the shooting is believed to be of a personal matter.

The names of the victims are being withheld until their families have been notified.